Such a database can provide different datasets of different content in different encrypted areas. Examples of such provided datasets are dynamic data, such as e.g. streaming video or streaming audio data. These can be transmitted as a continuous data stream, what is referred to as a “media stream”, from the database to a client or to a client device. The transmission of the continuous data stream takes place via an internet connection, for example. Text or image files would also be further examples of non-dynamic data.
In this case access to one or more of the encrypted areas can be permitted and consequently enabled for a specific group of clients or client devices.
The necessity for different access permissions for different groups of client devices, referred to as different access levels, arises for example as a result of statutory requirements which dictate that data provided via the internet must be classified, in particular in order to prevent unauthorized parties from accessing said data. An example of this is the well-known classification of video data or video films into FSK12, FSK16 or FSK18 and the like.
As far as the service provider of the datasets is concerned, the requirement for classification can also result from the provider's desire or responsibility to provide differentiated content to its different customers or customer communities.
Conventionally, the datasets requiring to be filtered or classified are filtered or classified offline on the server side prior to their transmission. This means disadvantageously that the entire content of the data must be filtered or classified before it can be made available for transmission in order to establish for which customer community or, as the case may be, for which clients belonging to a specific authorization, for example FSK16 or FSK18, specific datasets are to be or can be released.
To provide access control for the different client devices or groups of client devices there conventionally exists a central authority or instance, an application on a server of the database for example, which performs the filtering or classification of the datasets.
Disadvantageously, access control by the central authority or instance is static, i.e. the dataset is classified once in advance and subsequently retains its classification within the database.